Junheng Gao,Fu Tang,Yuting Li,Likang Zhang,An Hu,Shuo Li,Lidong Li
Fluorescent hydrogels have immense potential and are widely studied for on demand displays. Response rate of fluorophores upon stimuli within the hydrogel matrix is a key role to improve the timely responsiveness, but rare reports are elaborated on it. In this work, the photoisomeric spiropyran methacrylate (SPMA) is introduced into the poly (2-hydroxyethyl methacrylate) hydrogel to fabricate a stimuli-responsive fluorescent hydrogel. Interestingly, the photoresponse rate of SPMA in the hydrogel is greatly accelerated at the presence of F127 micelles than without it. Both of the absorbance and fluorescence intensity of the hydrogels at the photostationary state are improved obviously with micelles. Besides, the normalized absorbance and the fluorescence kinetic studies indicated a more than 2 times quicker isomerization process. The absolute fluorescence quantum yields of SPMA in the hydrogel is also increased. These can be attributed to the hydrophobic microenvironment provided by the F127 micelles that facilitated the conformation transition of SPMA. Thus, the synergetic effect of the increased amount of activable SPMA and the promoted speed of isomerization contributed to the accelerated photoresponse of the prepared hydrogel. Taking advantage of these virtues, a timely and multi-responsive on-demand information encryption system is realized.
Kun Fang,Rong Wang,Hua Zhang,Linjie Zhou,Ting Xu,Ying Xiao,Yang Zhou,Guorong Gao,Jing Chen,Donglei Liu,Fanrong Ai,Jun Fu
Acute wounds subject to frequent deformations are difficult to be treated because the healing process was easily interfered by external mechanical forces. Traditional wound dressings have limited efficacy because of their poor mechanical properties and skin adhesiveness and difficulty in the delivery of therapeutic drugs effectively. As such, tough and skin-adhesive wound dressings with sustainable and stimuli-responsive drug release properties for treatment of those wounds are highly desirable. For this purpose, we have developed a mechano-responsive poly(sulfobetaine methacrylate) hydrogel which aims to control the delivery of antibiotic drug upon application of mechanical forces. Diacrylated Pluronic F127 micelles were used as a macro-cross-linker of the hydrogel and loaded with hydrophobic antimicrobial drugs. The micelle-cross-linked hydrogel has excellent mechanical properties, with the ultimate tensile strength and tensile strain of up to 112 kPa and 1420%, respectively, and compressive stress of up to 1.41 MPa. Adhesiveness of the hydrogel to the skin tissue was ∼6 kPa, and it did not decrease significantly after repetitive adhesion cycles. Protein adsorption on the hydrogel was significantly inhibited compared to that on commercial wound dressings. Because of the mechano-responsive deformation of micelles, the release of drug from the hydrogel could be precisely controlled by the extent and cycles of mechanical loading and unloading, endowing the hydrogel with superior antibacterial property against both Gram-positive and Gram-negative bacteria. In addition, drug penetration into the skin tissue was enhanced by mechanical stress applied to the hydrogel. The micelle-cross-linked zwitterionic hydrogel also showed good cell biocompatibility, negligible skin irritation, and healing capacity to acute skin wounds in mice. Such a tough mechano-responsive hydrogel holds great promise as wound dressings for acute wounds subjected to frequent movements.
危险品化学品经营许可证（带存储）